Sliding clasp fasteners

ABSTRACT

A sliding clasp fastener is disclosed. The fastener comprises fastener strings of interlockable and U-shaped limbed fastener elements attached to respective fastener tapes by a line of stitching. The loops of the stitching pass over respective fastener elements to attach the fastener string to its fastener tape. Each string is anchored to its fastener tape by a filamentous element, such as a fine gauge cord or twisted textile thread, which meanders through spaces defined between the Ushaped limbs of the respective fastener elements in the longitudinal direction of the string. Also disclosed is a method of attaching a fastener string of U-shaped limbed fastener elements to a longitudinal fastener tape. The fastener tape and the string of fastener elements are fed past a stitching station at which a needle The an attaching machine is located. Te needle is used to insert a row of stitches to attach the fastener elements to the tape, and a filamentous element is fed in the longitudinal direction of the tape alternately in front of and behind the stitching needle transversely of the tape. The filamentous element passes through spaces defined between the limbs of the fastener elements to anchor the attaching stitching and hence to the tape.

Elited States Patent [191 Warburton et-al.

[ 1 Aug. '7, 1973 1 SLIDING CLASP FASTENERS [75] Inventors: Geoffrey Warburton; Ernest Robert Whetter, both of Cardiff, England [73] Assignee: Textron Limited, Edenbridge, Kent,

England [22] Filed: Aug. 4, 1971 [21] App]. No.: 168,881

Primary Examiner-James R. Boler ll rnvy-Richard (I. Sughrue, Robert J. Seas, Jr. 81 11.

[57] ABSTRACT A sliding clasp fastener is disclosed. The fastener comprises fastener strings of interlockable and U-shaped limbed fastener elements attached to respective fastener tapes by a line of stitching. The loops of the stitching pass over respective fastener elements to attach the fastener string to its fastener tape. Each string is anchored to its fastener tape by a filamentous element, such as a fine gauge cord or twisted textile thread, which meanders through spaces defined between the U-shaped limbs of the respective fastener elements in the longitudinal direction of the string. Also disclosed is a method of attaching a fastener string of U-shaped limbed fastener elements to a longitudinal fastener tape. The fastener tape and the string of fastener elements are fed past a stitching station at which a needle The an attaching machine is located. Te needle is used to insert a row of stitches to attach the fastener elements to the tape, and a filamentous element is fed in the longitudinal direction of the tape alternately in front of and behind the stitching needle transversely of the tape. The filamentous element passes through spaces defined between the limbs of the fastener elements to anchor the attaching stitching and hence to the tape.

5 Clalms, 4 Drawing Figures SLIDING CLASP FASTENERS BACKGROUND OF THE INVENTION This invention relates to a sliding clasp fastener and a method of producing the same. More especially, the invention relates to a method of attaching strings of interlockable fastener elements to a fastener tape and to sliding clasp fasteners having tapes with strings of interlockable fastener elements so attached. A string of interlockable fastener elements is formed by producing a meander-like chain of elements and folding the chain about axes in its longitudinal direction, each individual element in the string so formed being of U-shaped section, joined (except end elements of a string) to its immediately preceding and succeeding element by a link portion extending in the longitudinal direction of the string, and the base of each U-shaped element being deformed to form a coupling portion.

The present invention is concerned with the attaching strings of interlockable fastener elements to fastener tapes, and sliding clasp fasteners with tapes having strings so attached.

It has been known to attach coil-type strings of interlockable fastener elements to one side of the tape only giving the sliding clasp fastener tape a desired feature known as flat-back," which has the advantage that, when the fastener is applied to a garment, the back surface, i.e. that worn nearer to the wearer's body, is free from protusions With strings of interlockable fasteners, it has hitherto been the practice to attach the string to the tape edge with portions of each element on either side of the tape. This had the disadvantage that a sliding clasp fastener comprising tapes so formed when applied to a garment, had protusions on the surface adjacent to the wearers body and was therefore less pleasant to wear.

Coil-type strings have been attached to the tape edge on one side only, to give the desirable feature, known as a flat-back" fastener, but with the addition of a cord running through the coils thereof. This cord ensured that the stitching, which pierced the cord when the coil-type string was attached to the fastener tape, was properly anchored.

Consequently, sliding clasp fasteners have been sold which comprise tapes having coil-type fasteners simply attached to one side thereof by conventional stitching. It was very quickly discovered, however, that such sliding clasp fasteners had shorter life span owing to the tendency for elements of the coil type strings of fasteners element to be pushed out of the attaching thread loops causing a break down of the fastener to occur.

When attaching strings of interlockable elements to fastener tapes, the use of cord or braid is possible although increasingly difficult due to the problem of locating the cord or braid to ensure its being pierced by the attaching thread and secondly to avoid excessive thickness and cost.

SUMMARY OF THE INVENTION According to the present invention, there is provided a sliding clasp fastener in which each of the fastener tapes has a fastener string of interlockable fastener elements attached thereto by at least one row of stitching, and wherein at least one filamentous element is arranged to pass in meander fashion through the loops of the or each row of stitching for the purpose of anchoring each string of interlockable fastener elements to its respective tape, the or each filamentous element passing through the spaces defined between U-shaped limbs of the interlockable fastener elements in the longitudinal direction of the string.

The filamentous element may be an additional attaching thread, or a fine gauge cord or filament. The term fine being employed to distinguish such a cord from a filler cord which occupies substantially all the space defined by the coils of the coil-type interlockable fastener elements and which, when employed hitherto, the stitching threads were intended to pierce in order to anchor the coil-type string of interlockable elements to its respective tape.

According to a further aspect of this invention, there is provided a method of attaching a string of interlockable fastener elements to a fastener tape, comprising the steps of feeding the fastener tape and the string of interlockable fastener elements past a stitching location, inserting at least one row of stitches which attach the string of interlockabe fastener elements to the fastener tape with a loop or loops of the stitching passing over a limb of eachfastener element, the stitching being effected at the stitching location by means of a needle of an attaching machine, and, for the purpose of anchoring each string of interlockable fastener elements to its tape to restrain individual elements of said string against being displaced out of the row or rows of attaching stitches, feeding at least one filamentous element in the longitudinal direction of the tape alternately in front of and behind the stitching needle transversely of the tape, the or each filamentous element passing through the spaces defined between U-shaped limbs of the interlockable fastener elements in the longitudinal direction of the string.

Preferably, the respective filamentous elements of at least one pair of filamentous elements are fed alternatelyin front of and behind the stitching thread or threads in an anti-phase relationship.

The feed of the tape and the string of interlockable fastener elements past the stitching location is or preferably, stepwise with each step corresponding to the pitch distance taken centre to centre of the spaces between adjacent elements of said string.

The or each filamentous element may be guided by means of a reciprocating guide member synchronised with the movement of the stitching needle. The or each row of attaching stitching may be formed as a twothread chain stitch, a lock stitch or a single thread chain stitch.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention will now be more particularly described with reference to the accompanying drawings, in which:

FIG. 1 shows a plan view of a string of interlockable fastener elements attached to a fastener tape by a method provided by the invention;

FIG. 2 shows a section taken on the line II-II of FIG.

FIG. 3 shows a section taken on the line IIIIII of FIG. 2; and

FIG. 4 illustrates, schematically and in plan view, the method of attaching the string of FIG. 1 to its fastener tape.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 3 shows a Wendel-type string I of interlockable fastener elements 3 attached to a fastener tape 2 by a method provided by the present invention. The string 1 of interlockable fastener elements 3 is ofa generally known construction and formed from plastics material. The free ends of the individual elements 3 are deformed to provide coupling portions 4 and joined to their preceeding and succeeding elements in the string by link portions 7 (except the end elements). As can be seen from FIGS. 1 and 2, the string I is attached to the fastener tape 2 by means of a line of stitching S. This stitching 5 may be a line of two-threaded chain stitches, or a line of lock stitches. For the purpose of anchoring the string of interlockable fastener elements 1 to its fastener tape 2, a filamentous element 6 is arranged to pass in meander fashion through the loops 8 of the stitching 5. This filamentous element 6 may be an additional twisted textile thread or a fine gauge cord full stop. As shown in FIGS. 2 and 3, the element 6 passes through the spaces defined between the U-shaped limbs 3 (FIG. 3) of the interlockable fastener elements in the longitudinal direction of the string (arrow A).

After attachment, the relative positions of the string 1 and fastener tape 2 is such that the coupling portions 4 project slightly beyond the free edge 9 of the tape 2. By appropriate choice of the extent to which these coupling portions project, one may ensure that, when a sliding clasp fastener comprising two such tapes is closed by a slider (not shown), the free edges 9 of the respective tapes abut one another to conceal the inter lockable fastener elements 3, when viewed from the back.

The filamentous element 6 ensures that despite pressure on the coupling portions 4 in the direction of the arrow B, FIG. 1 (Le. laterally of the longitudinal direction of the tape), the individual elements 3 of the string 1 are restrained from being pushed out of respectively associated individual ones of loops 8 of the stitching 5. Thus, this construction tends to prevent breakdown of the sliding clasp fastener due to individual fastener elements 3 being pushed out of the loops 8, as might tend to occur in the absence of the element 6.

The invention also embraces a method of attaching Wendel-type strings of interlockable fastener elements 1 to fastener tapes 2 which is effected, as illustrated schematically in FIG. 4, to produce a tape 2 with a fastener string 1 attached as shown in FIGS. 1 to 3 (corresponding numerals designate the same features).

In order to attach the string I of interlockable fastener elements 3 to the fastener tape 2, the fastener tape 2 and the string 1 are fed past a stitching location, the position of which is generally designated by the reference numeral 10. The string 1 of interlockable fastener elements 3 is fed towards the stitching location 10 by means of a rotatable feed drum or wheel, generally designated by the reference II, which on its periphery is provided with regularly spaced channels 16 interposed by spacing elements 13. The drum 11 is rotated by means of'a central drive shaft 15. Each of the channels 16 is adapted to receive a coupling portion 4 of an individual interlockable fastener element 5. The fastener tape 2 together with that portion of the string 1 attached thereto (after stitching has commenced) are fed in conventional manner, for example, by a knurled puller wheel suitably driven (not shown).

As the string 1 and fastener tape 2 are fed through the stitching location 10, a needle 12 of an attaching machine, such as a sewing machine (not shown), inserts an attaching thread 5 to form a plurality of stitching loops 8 which attach the string 1 of interlockable fastener elements 3 to the fastener tape 2 with each loop 8 of the attaching thread 5 passing over a limb 3 of a fastener element (FIGS. 1 and 2). For the purpose of anchoring each string 1 of interlockable fastener elements 3 to its tape in order to restrain individual elements 3 of said string 1 from being pushed out of the loops 8 of the line of attaching stitching 5, a filamentous element 6, which is being fed by means (not shown) in the longitudinal direction of the tape 2, is arranged alternately in front of and behind the stitching needle with respect to the lateral direction of the tape 2 (arrow B of FIG. 1 and arrow C of FIG. 4). This is effected by reciprocating the filamentous element 6 so that it lies alternately in front of and behind the needle 12 during, for example, successive stitches thereof, by means of a reciprocatingguide member 14, the movement of which is synchronised with the stitching movement of the needle or needles 12. The guide member 14, which is only shown schematically, may be a reciprocatable sliding member driven by the sewing machine. The filamentous element 6 is at the start of the attaching operation so arranged that it passes through the spaces (FIG. 3) defined between the U-shaped limbs 3 of the interlockable fastener elements in the longitudinal direction of the string (FIG. 1, arrow A).

The feed of the tape 2 and the Wendel-type string 1 of interlockable fastener elements 3 passed to the stitching location 10 may be continuous or stepwise, but, preferably, stepwise with each step corresponding to the pitch distance taken centre to centre of the spaces between adjacent elements 3 of said string 1, or a multiple or sub-multiple thereof in a manner known per se.

The sewing machine may be adapted to insert a row of attaching stitches formed as a two-thread chin stitch, or a lock stitch in the manner in which such machines are conventionally employed.

As shown in FIG. 4,-a second filamentous element 6' may be fed simultaneously with the filamentous element 6. The filamentous element 6 is guided by a guide member 14', which may be a reciprocatable sliding member driven by the sewing machine to reciprocate in the direction C'. Thus, the feeding step may comprise the step of feeding respective filamentous elements 6 and 6' of at least one pair of filamentous elements alternately to one side and then to the other side of a thread or threads defining the line or lines of attaching stitching 5.

What is claimed is:

l. A sliding clasp fastener portion comprising in combination:

a longitudinal fastener tape;

a plurality of interlockable and substantially U- shaped limbed fastener elements mutually interconnected by link portions to form a meander-like chain extending in the longitudinal direction of said tape;

at least one line of stitching comprising a plurality of loops each passing over a respective fastener element to attach said chain of fastener elements to said fastener tape;

at least one filamentous element passing through spaces defined between said limbs of said fastener elements in the longitudinal direction of said chain and passing through each one of said loops, said at least one filamentous element passing through successive ones of said loops from alternately opposite sides of said at least one line of stitching.

2. A method of attaching a plurality of interlockable U-shaped limbed fastener elements mutually interconnected by link portions to form a meander-like chain to a longitudinal fastener tape, the method comprising in combination the steps of:

feeding said fastener tape and said chain of fastener elements past a stitching station at which a needle of an attaching machine is located;

inserting at least one line of stitching to attach said chain of fastener elements to said tape with each loop of said at least one line of stitching passing over a respective one of said fastener elements; and feeding at least one filamentous element in the longitudinal direction of said tape alternately to one side and then to the other side of said needle transversely of said tape, said at least one filamentous element passing through spaces defined between said limbs of said fastener elements in the longitudinal direction of said chain and passing through each one of said loops, and said at least one filamentous element passing through successive ones of said loops from alternately opposite sides of said at least one line of stitching.

3. A method as defined in claim 2, wherein said first mentioned feeding step comprises the step of feeding in a stepwise manner said tape and said chainbf fastener elements past said stitching station, with each feed step corresponding to the pitch distance taken centre to centre of the spaces between adjacent ones of said fastener elements.

4. A method as defined in claim 2, wherein said last mentioned feeding step comprises the step of feeding respective filamentous elements of at least one pair of filamentous elements alternately to one side and then to the other side of a thread defining said at least one line of stitching.

5. A method as defined in claim 2, wherein said at least one filamentous element is guided by means of a guide member reciprocating synchronously with the movement of said needle. 

1. A sliding clasp fastener portion comprising in combination: a longitudinal fastener tape; a plurality of interlockable and substantially U-shaped limbed fastener elements mutually interconnected by link portions to form a meander-like chain extending in the longitudinal direction of said tape; at least one line of stitching comprising a plurality of loops each passing over a respective fastener element to attach said chain of fastener elements to said fastener tape; at least one filamentous element passing through spaces defined between said limbs of said fastener elements in the longitudinal direction of said chain and passing through each one of said loops, said at least one filamentous element passing through successive ones of said loops from alternately opposite sides of said at least one line of stitching.
 2. A method of attaching a plurality of interlockable U-shaped limbed fastener elements mutually interconnected by link portions to form a meander-like chain to a longitudinal fastener tape, the method comprising in combination the steps of: feeding said fastener tape and said chain of fastener elements past a stitching station at which a needle of an attaching machine is located; inserting at least one line of stitching to attach said chain of fastener elements to said tape with each loop of said at least one line oF stitching passing over a respective one of said fastener elements; and feeding at least one filamentous element in the longitudinal direction of said tape alternately to one side and then to the other side of said needle transversely of said tape, said at least one filamentous element passing through spaces defined between said limbs of said fastener elements in the longitudinal direction of said chain and passing through each one of said loops, and said at least one filamentous element passing through successive ones of said loops from alternately opposite sides of said at least one line of stitching.
 3. A method as defined in claim 2, wherein said first mentioned feeding step comprises the step of feeding in a stepwise manner said tape and said chain of fastener elements past said stitching station, with each feed step corresponding to the pitch distance taken centre to centre of the spaces between adjacent ones of said fastener elements.
 4. A method as defined in claim 2, wherein said last mentioned feeding step comprises the step of feeding respective filamentous elements of at least one pair of filamentous elements alternately to one side and then to the other side of a thread defining said at least one line of stitching.
 5. A method as defined in claim 2, wherein said at least one filamentous element is guided by means of a guide member reciprocating synchronously with the movement of said needle. 